Calculator.



PATENTED MAY 5, 1908.

J. E. DUNCAN.

CALCULATOR.

APPLICATION FILED MAY 26, 1906.

Qwi/tweooaa NIT D STATES reg ons. onnros.

AMES DUNCAN, or SILOAM sssmos, ARKANSAS. v

osLcULA'roR.

No. 886,588. 7 l5 "icution of Letters Patent. Patented May 5, 1908.

Application filed May; 26, 1906. SerialNo. 318,970,

EuounnDouhe of Amen k in ZEloeui Springs, State of ts, have ovented a new and useful tor, Oil which the following e specilicotionf The present invention relates to calculutors, and tbeprincipel object is to provide 9. simple structure, which is easily understood, siiid by which computations that ordinarily time, may be quickly and ecouresponding ports in all the figures oi the drmving.

In the embodiment illustrated, 2. base 6 is employed, on which rotetebly mounted a. com'giuising side wells 2 at top end. 21 ,ottoin uhe en s oi the c: sing being open.

1 :nounti' wrobly con scts oils boss iii, carried by the bottom well, nd he. depending gods-eon 1i 1'- in e J t 12,

l n oi on upstsnah c by the b 1 of the sioo v. i oil with inw; t nding constituting guide Joys on .y mounts l slide pistes llioi suostontis. J unelengi theossingnnd having e 1d tees lo projecting from the open zeroes, that eompw.

Fig. 5 a plan View of one of the ends oi? said 111g. The sh. s provided two, may be resorted to Without depertin tables of calculations 19, said tables being disposed on. opposite sides of the slots end on ofiposite end-portions o f the slide, as dis- 0 osed in Fig. 5.

' The tables of calculations shown in Fig. 5, representthe calculations of interest at five percent. and six percent. on from one to ten thousand dollars for one day and two days respectively, the designations on the tabs 16, shown in Fig. 5,- re resenting the number. of days calculated. 'Fhe tables, as shown, we divided by transverse lines and every other line is subdivided. The figures in the undivided lines are the amo'unts on which the interest is calculated, while the figures in the subdivisions are the results, or inv other words, the amounts of interest.

To find the interest on any oinount, for ere ample, the interest on $1,570, ut liveper cent for one day, it is only necessary to draw out the end of the slide having the .i teb thereon, thereupon it can be escerteined thut the interest on $1,000 for one day will be fourteen cents; for500 in the hundreds column will be seven cents, and for $270. in the tens column will be one cent, making a total of twenty-two cents on the amount ebove stated at live per cent for one day. 11 two days interest is to be calculated, it is only necessary to revolve the casing, and draw out the opposite side of the slide having the designation 2 on the tab, whereupon the some rocess is carried out. it will thus be seen t mt the tables of calculations are double the number of slides employed and the stop oin will prohibit the ex osure of more than hell the slide in either irection. liiioreover by removing the pin, the slides con be re moved from the casing, and otl'iers substi 9 tuted therefor.

From the foregoing, it is thought that the construction, operation, and many edvon" toges oi the herein described inve ition, will be a )perent to those skilled in the art, Without 'iurthe'r description, and it will be under-- stood that various changes in the size, shape, proportion, and minor details of construe from the s irit or sacrificing any of the out vantages o the invention.

Having thus fully described my invention, what I claim as new, end desire to secure by Letters Patent, is:

1. 111 a calculator of the character set 110 forth, the combination with a. casing having on open end, of a plurality of slides movebly mounted in the casing and movableoutthe casing and engagin a l the slides for limitin their said out-want movement.

2. In a calculator of the character set ably mounted in the casing and movable outwardly through the open ortion thereof, said slides being provided with tables of calculations and having slots, and a pin passing through the slots of the various sl des to limit the outward movement of said slides.

4. In a calculator of the character set forth,

the combination with a casing having op 0- site open ends, of a slide movably inounter in the casing and having its end portions respectively moved outwardly through the open ends of the casin", and tables of calculations located on said. slide and exposed in its out- Ward movement in opposite directions.

5. In a calculator oi the character set forth, the combination with a casing having opposite open ends, of a slide movably'mounted into the casing and having its end portions respectively movable outwardly through the open end of the casing, tables of calculations located on said slide and exposed on its outward movement in opposite directions, and means for limiting the outward movement of the slide in either direction.

-6. In a calculator of the character set forth, the combination with a casing having opposite open ends, of a slide movably mounted in the casing, and having its end portions respectively movable outwardly through the open ends thereof, said slide being: provided with a longitudinally disposed slot tables of calculations located on theend portions of the slide and exposed on its opposite outward movement in opposite directions, and a. slot engaging in the slot and limiting the -rnovementof the slide in both directions.

7. In a calculator of the character set forth, the combination with a casin hating open ends and provided with guir e-Ways on its side Walls, of a plurality of slides movably mounted on the guide-ways and movable in opposite directions outwardl through the open ends thereof, said slides eing provided with longitudinally disposed slots, tables of calculations located on the end portions of the slide and exposed on their outward movement, and a stop pin extending through the casing and through the slots in the slides.

8. In a calculator of the character set forth,

the combination with. a casing consisting of a top, bottom and sides, of a plurality of slides movable in the casing and having centrally dis osed slots, and a rod located verticall an centrally within the casin and extend ing from top to bottom thereol said rod be; ing located in the slots of the slide.

9. In a calculator of the character set forth, the combination with a casin consisting of a top, bottom and sides, of guide-Ways located horizontally on the inner Walls oi the sides of the casing, a plurality of slotted slides having tables of calculations thereon and mounted to operate on the guideways in the casing, a rod or'stop pin vertically and centrally lccated withinthe casing and disposed in the slots of the slides, and a base upon which the casing is rotatably mounted.

JAMES EUGENE DUNCAN.

' Witnesses:

F. It. TAYLOR, J. J. MCCLUNG. 

